We will investigate the effects of alcohol intoxication and age on aircraft pilot performance. Our research in the previous funding period found evidence that alcohol and age cumulatively impair pilots' ability to understand and execute air control instructions during a simulated flight. We interpreted this finding in terms of a model that proposes that alcohol and age impair communication processes in working memory by restricting working memory capacity. All three of the proposed experiments further test if alcohol and pilot age cumulatively impair pilot performance. In addition, each experiment examines if difficult controller instructions further impair performance by taxing working memory. We will test hypotheses about the impact of three controller instruction variables on performance: (1) Rapid presentation of instructions (2) Nonstandard presentation order of instructions, and (3) Instructions with high information load. The experiments will be conducted in our computerized flight simulator laboratory. We are able to generate and quantify a wide range of simulated flights that test aircraft target detection and avoidance, engine emergency detection, and other critical pilot abilities, in addition to routine aircraft control and communication performance. Data will be automatically recorded and stored on computer, and later analyzed by standard ANCOVA and correlational analyses. The results will help us understand cognitive components of complex human-machine task performance, which aspects of complex task performance are impaired by alcohol and age, and the role of air traffic control instructions, alcohol, and age for safe flight.